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Proton Products SL mini and SLR mini Series Speed and Length Gauges Instruction Manual - issue 1s
Read data from a block of consecutive output parameters
Use Modbus function “04” (Read Input Registers) to write
to a block of consecutive input parameters.
Modbus query format
Hex
Modbus response format
Hex
Slave Modbus address
(Gauge Modbus address)
01
Slave Modbus address
(Gauge Modbus address)
01
Modbus function code
04
Modbus function code
04
Starting address
(Starting output parameter
address)
High
byte
00
Byte count
N = (2 × Number of points)
06
Low
byte
02
Data word 0
(corresponds to output DW2)
High
byte
07
Number of points
(Output parameter word
count)
High
byte
00
Low
byte
D0
Low
byte
03
Data word 1
(corresponds to output DW3)
High
byte
05
Low
byte
DC
Data word 2
[(N/2)
–
1]
(corresponds to output DW4)
High
byte
09
Low
byte
C4
The response contains the output parameter values requested in the query; its length is dependent on
the number of output parameters requested.
